High gain preamps [30db +]
Why? would somebody/anybody!! want to reduce the sources signal level down to a miniscule amount with the volume control (yes it passive even in a an active preamp), only then to boost the **** out of it with huge gain from an active line stage after that volume control????????????
If you do, your throwing away "precious high source level", down to what a phono cartridge puts out, just so then all the noise and **** etc etc gets boosted back up again by that high gain output stage
Nelson Pass says it all here:
“We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.
Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.
Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.
What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.
And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.”
Cheers George
